<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>

<div id="app">
    {{msg+ '@@@@@@@'}}
</div>

<script src="../../vue.js"></script>
<script>
    let app = new Vue({
                el : '#app',
                data:{
                    msg : 'helloworld'
                }
              })

    setTimeout(function(){
        app.msg = 'hello 响应式'
    },3000)          
</script>
</body>
</html>